you wont feel anything as far as power goes.nor will you actually see anything for economy increase (however it doesn't mean it's not there.)
the vac pump tuns on and off as required.you simply hook up a relay to supply it power when the key is turned on like you would a e-pump for fuel,and done.
it will run a few secs when you first turn the key on,and whenever you change HVAC settings.i personally used no canister as i don't swap settings much.you have 3-4 times going from vent to defrost for example until it kicks back on for another few seconds without a canister.
your C6 requires vac.you'll need to look into that,or someone else will need to help with info.id guess you might want to make sure to use a canister/reservoir.should be one already on your truck.
there is for the 93,but it was small,and i didn't want to vac the whole system,just the HVAC.
you'll probably just keep the whole stock vac line system.problem is,if you do that,you might want to replace all the vac lines cus a leak will mean the pump runs until it burns up.you could also use some sort of timer,where it passes current through for a max of 3-5 mins and kicks off,to help reduce the risk of pump burning up.